The Rosetta Stone

The Rosetta Stone made it possible to understand that hieroglyphics is not a pictorial language. That is to say that each symbol did not represent the thing it depicts, but rather it is phonetic, each symbol represents sounds. This was made possible because the Rosetta Stone is inscribed in two languages, namely Egyptian (in its Demotic phase) in two different scripts (Hieroglyphics, Demotic) and Greek.